Open Source RTOS

http://www.osrtos.com/

 

 

Name	License	Platforms	Description	Last updated
FreeRTOS	Modified GPL	MSP430 ARM AVR ColdFire PIC x86	FreeRTOS is a popular real-time operating system for embedded devices, being ported to 31 microcontrollers. It is distributed under the GPL with an optional exception.	2015-Oct-16
Contiki	BSD	MSP430 ARM AVR 8051	Contiki is an open source operating system for the Internet of Things. Contiki connects tiny low-cost, low-power microcontrollers to the Internet.	2015-Aug-26
ChibiOS/RT	Modified GPL	MSP430 AVR	ChibiOS is a complete development environment for embedded applications including RTOS, an HAL, peripheral drivers, support files and a development environment.	2016-Jan-23
RTEMS	GPL	ARM x86 MIPS PowerPC m68k	RTEMS is an open source RTOS that supports open standard application programming interfaces such as POSIX. It is used in space flight, medical, networking and many more embedded devices.	2015-Sep-11
NuttX	BSD	ARM AVR 8051 x86	NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 32-bit microcontroller environments, the primary governing standards in NuttX are Posix and ANSI standards.	2015-Oct-01
RT-Thread	GPL	x86 MIPS PowerPC	RT-Thread is an open source real-time operating system for embedded devices from China. RT-Thread RTOS is a scalable real-time operating system: a tiny kernel for ARM Cortex-M0, Cortex-M3/4, or a full feature system in ARM Cortex-A8, ARM Cortex-A9 DualCor	2015-Feb-01
RTAI	GPL	ARM x86 PowerPC x86_64 m68k	RTAI is the RealTime Application Interface for Linux - which lets you write applications with strict timing constraints for your favourite operating system. The RTAI distribution includes RTAI-Lab, a tool chain to convert block diagrams into RTAI executab	2015-Jan-28
Xenomai	GPL	ARM x86 PowerPC	Xenomai is a real-time development framework cooperating with the Linux kernel, in order to provide a pervasive, interface-agnostic, hard real-time support to user-space applications, seamlessly integrated into the GNU/Linux environment.	2014-Sep-25
TI-RTOS Kernel	Other		TI-RTOS Kernel (formerly known as SYS/BIOS™) is an advanced, real-time kernel for use in a wide range of DSPs, ARMs, and microcontrollers.	2015-Aug-19
Atomthreads	BSD	AVR	Atomthreads is a free, lightweight, portable, real-time scheduler for embedded systems.	2015-Feb-24
Erika Enterprise	Modified GPL	MSP430 ARM AVR	Erika Enterprise is the first open-source Free RTOS that has been certified OSEK/VDX compliant!.	2015-Mar-07
Freescale MQX	Other	ARM ColdFire	The Freescale MQX Real-Time Operating System (RTOS) provides real-time performance within a small, configurable footprint. The RTOS is tightly integrated with the latest 32-bit MCUs and MPUs from Freescale and is provided with commonly used device drivers	2015-Mar-07
Fusion Embedded RTOS	Other	ARM PowerPC	The Fusion Embedded RTOS (Real-Time Operating System) from Unicoi Systems is a Real-Time OS designed and optimized for networking and media-centric processors.	2015-Mar-08
MARK3	BSD	AVR	Mark3 is a sophisticated, modern RTOS and application development platform, targeted towards a growing list of today's most compelling embedded devices.	2015-Mar-08
Nut/OS	GPL	AVR ColdFire	Nut/OS is an intentionally simple RTOS for the ATmega128, which provides a minimum of services to run Nut/Net, the TCP/IP stack.	2014-Nov-20
RIOT	Modified GPL	MSP430 AVR	RIOT is an operating system designed for the particular requirements of Internet of Things (IoT) scenarios.	2015-Dec-04
distortos	Mozilla Public License Version 2.0	ARM	Distortos is an advanced RTOS written in C++11.	2016-Feb-13
BitThunder	GNU GPL version 2.0	ARM	A Reliable Real-Time Operating System & Application Framework.	2015-Dec-13
DSPnano	Other		The DSPnano POSIX RTOS supports general purpose MCU, DSP and DSC 16 bit architectures with as little as 1K of RAM and 6K of flash.	2015-Nov-30
Unison	Other		Unison supports general purpose microcontrollers (MCUs), digital signal processors (DSPs), FPGAs, microprocessors (MPUs) and digital signal controllers (DSCs) 32 bit architectures with as little as 1K of RAM and 2K of flash.	2015-Nov-30
CoActionOS	Other		CoActionOS is a real-time, embedded operating system for the ARM Cortex-M3 architecture.	2014-Nov-14
BRTOS	MIT	MSP430 AVR ColdFire PIC	BRTOS is a lightweight preemptive real time operating system designed for low end microcontrollers.	2014-Dec-14

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RTOSs not under active development ( Not updated for more than 2 years )

Name	License	Platforms	Description	Last updated
Femto OS	GPL	AVR	Femto OS: RTOS for small MCU's like AVR.	2012-Dec-09
BeRTOS	Modified GPL	AVR x86 PowerPC x86_64	BeRTOS is a real time open source operating system supplied with drivers and libraries designed for the rapid development of embedded software.	2011-Aug-08
DuinOS	Other	AVR	DuinOS is a small multithreading real time operating system (RTOS), based on the FreeRTOS kernel, for Arduino compatible boards.	2012-Jan-08
eCos	GPL	ARM MIPS PowerPC	eCos is a free open source real-time operating system intended for embedded applications. The highly configurable nature of eCos allows the operating system to be customised to precise application requirements, delivering the best possible run-time perfor	2013-Aug-25
FunkOS	Other	MSP430 AVR	FunkOS is an RTOS for 8-32 bit MCUs including AVR, MSP430, and Cortex M3. Both C and C++ kernels avaiable. Key features include preemption, periodic events, device drivers, and mutex/semaphores. Includes a variety of graphics and filesystem middleware.	2013-Apr-23
Prex	BSD	ARM x86	Prex is an open source, royalty-free, real-time operating system for embedded systems. It is designed and implemented for resource-constrained systems that require predictable timing behavior. The highly portable code of Prex is written in 100% ANSI C bas	2009-Oct-01
scmRTOS	MIT	MSP430 AVR	scmRTOS stands for Single-Chip Microcontroller Real-Time Operating System.	2012-Dec-01
TNKernel	GPL	MSP430 ColdFire	TNKernel is a compact and very fast real-time kernel for the embedded 32/16/8 bits microprocessors.	2013-Jun-06
Protothreads	BSD	AVR 8051	Protothreads are extremely lightweight stackless threads designed for severely memory constrained systems.	2005-Apr-08